Remove use of exit(2) in configure test.

[Ralf Wildenhues]

Jeff reported this off-list, applied to master as rather obvious.

Cheers, and thanks!
Ralf

2008-08-11  Ralf Wildenhues  <[EMAIL PROTECTED]>

        Remove use of exit in configure test sources.
        * libltdl/m4/libtool.m4 (_LT_TRY_DLOPEN_SELF): Return from main,
        to avoid using undeclared exit.
        Report against OpenMPI from Coverity via Jeff Squyres.

diff --git a/libltdl/m4/libtool.m4 b/libltdl/m4/libtool.m4
index b9d0fc9..79f58f8 100644
--- a/libltdl/m4/libtool.m4
+++ b/libltdl/m4/libtool.m4
@@ -1684,10 +1684,6 @@ else
 #  endif
 #endif
 
-#ifdef __cplusplus
-extern "C" void exit (int);
-#endif
-
 void fnord() { int i=42;}
 int main ()
 {
@@ -1703,7 +1699,7 @@ int main ()
   else
     puts (dlerror ());
 
-    exit (status);
+  return status;
 }]
 _LT_EOF
   if AC_TRY_EVAL(ac_link) && test -s conftest${ac_exeext} 2>/dev/null; then